From: Steven Rostedt <rostedt@goodmis.org>
To: Yafang Shao <laoar.shao@gmail.com>
Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
kafai@fb.com, songliubraving@fb.com, yhs@fb.com,
john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com,
haoluo@google.com, jolsa@kernel.org, mhiramat@kernel.org,
bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH bpf-next 5/6] bpf: Improve tracing recursion prevention mechanism
Date: Thu, 27 Apr 2023 11:36:02 -0400 [thread overview]
Message-ID: <20230427113602.0e49c0d1@gandalf.local.home> (raw)
In-Reply-To: <CALOAHbDRSNvihv5n0jJpAsK3onezRRipO78RG3rAf3LGgkzYHg@mail.gmail.com>
On Thu, 27 Apr 2023 23:23:31 +0800
Yafang Shao <laoar.shao@gmail.com> wrote:
> > But I thought you can run a bpf_prog from another bpf_prog. So you don't
> > want to prevent it. You need other logic to detect if it was not suppose to
> > recurs.
> >
>
> If so, we have to keep the prog->active to prevent it, then I'm not
> sure if it is worth adding test_recursion_*().
I thought that the whole point of this exercise was because the
migrate_disable() itself could be traced (or call something that can), and
that's outside of prog->active protection. Which the test_recursion_*()
code was created for.
-- Steve
next prev parent reply other threads:[~2023-04-27 15:36 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-17 15:47 [PATCH bpf-next 0/6] bpf: Tracing recursion prevention mechanism improvement Yafang Shao
2023-04-17 15:47 ` [PATCH bpf-next 1/6] bpf: Add __rcu_read_{lock,unlock} into btf id deny list Yafang Shao
2023-04-17 15:47 ` [PATCH bpf-next 2/6] tracing: Add generic test_recursion_try_acquire() Yafang Shao
2023-04-20 6:51 ` Masami Hiramatsu
2023-04-17 15:47 ` [PATCH bpf-next 3/6] tracing: Add the comment for allowing one single recursion in process context Yafang Shao
2023-04-17 15:47 ` [PATCH bpf-next 4/6] selftests/bpf: Allow one single recursion in fentry recursion test Yafang Shao
2023-04-17 15:47 ` [PATCH bpf-next 5/6] bpf: Improve tracing recursion prevention mechanism Yafang Shao
2023-04-17 20:14 ` Alexei Starovoitov
2023-04-18 1:49 ` Yafang Shao
2023-04-18 15:38 ` Alexei Starovoitov
2023-04-19 11:46 ` Yafang Shao
[not found] ` <CAADnVQ+FO-+1OALTtgVkcpH3Adc6xS9qjzORyq2vwVtwY2UoxQ@mail.gmail.com>
2023-04-24 21:40 ` Steven Rostedt
2023-04-27 9:57 ` Yafang Shao
2023-04-27 12:15 ` Yafang Shao
2023-04-27 12:35 ` Yafang Shao
2023-04-17 23:29 ` kernel test robot
2023-04-27 13:26 ` Steven Rostedt
2023-04-27 14:22 ` Yafang Shao
2023-04-27 15:18 ` Steven Rostedt
2023-04-27 15:23 ` Yafang Shao
2023-04-27 15:36 ` Steven Rostedt [this message]
2023-04-27 15:39 ` Alexei Starovoitov
2023-04-27 15:43 ` Yafang Shao
2023-04-27 15:46 ` Steven Rostedt
2023-04-17 15:47 ` [PATCH bpf-next 6/6] bpf: Remove some denied functions from the btf id deny list Yafang Shao
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